The team’s acting chairman and CEO then heard the roar from Lions fans and immediately knew something had gone wrong for his rookie quarterback in the season opener Monday night.

Darnold threw an interception on his first pass that was returned for a touchdown.

“I looked through the glass wall of the elevator, and I saw a replay of the pick,” Johnson recalled Wednesday in his first formal chat with reporters since last season ended. “My heart sank, like every Jets fan’s heart sank at that point.”

Johnson, running the team while brother Woody is serving as the U.S. ambassador to the U.K., also added that his “heart stopped” but did not get down on the 21-year-old Darnold. He also knew the youngster would bounce right back.

“One of the things we’ve seen from Sam in college, in the springtime and in training camp is that he has an amazing ability to put adversity behind him,” Johnson said. “When something goes wrong, he quickly pivots to what comes next. I had great faith in him even after that pick-6.

“I thought, ‘OK, he’s been punched in the face. Let’s see how he responds.’ And I did not lose heart entirely.”

Darnold delivered, going 16 of 21 for 198 yards and two touchdowns while helping the Jets to a stunning 48-17 season-opening victory.

“I think he’s one of those old souls,” Johnson said. “He’s wise beyond his years. Certainly his decision-making to this point has indicated so. He’s very steady. He’s not prone to big highs or lows.”

The Jets traded up three spots from No. 6 in March to assure themselves of getting a franchise-type quarterback. After Cleveland took quarterback Baker Mayfield first overall and the Giants selected running back Saquon Barkley, Johnson and the Jets knew they would get the guy they wanted all along in Darnold.

The owner was still excited shortly after the draft when he told reporters that the selection of Darnold could be a moment people look at 20 years from now as the move that made the Jets great again.

A 50-year Super Bowl drought can do that, and Johnson acknowledged Wednesday that he was “maybe a little more enthusiastic than I should be, and things got away from me a little bit.”

But, Johnson added that he hopes time — and Darnold — will prove him right someday.

“I think the trade up to (No.) 3 was pivotal,” Johnson said. “It’s maybe the most important decision that the organization has made in a long time. I mean, certainly in years.”

Johnson made sure to not raise expectations for this year’s team, reiterating that there’s no playoff mandate because he thinks those can be counterproductive.

Instead, he hopes to see progress from his team and coaching staff. Not that he can’t help but feel good with such a rousing start to the season behind their rookie QB.

“This is one game,” he said. “I think the fans can legitimately be excited. They should be. But it’s one game. Sam sees it as that. The organization does. We’re going to try to move forward with that in mind.”

Here are some other comments from Johnson:

— On whether he might continue in his current role when his brother returns from his position as U.S. ambassador: “Look, I’m looking forward to my brother coming back in a few years. He’s a great leader. But, no question, I’m hoping to have a larger role at that point than I had prior. I think he’d welcome that. I know he would because I think I have a new perspective at this point that would be valuable for the franchise.”

— On being the team’s CEO: “It’s a great gig.”

— On fans being excited about the potential of the Jets moving forward: “Next year, we have the most money in free agency (among NFL teams) and I think there’s reasonably going to be some interesting free agents coming out. It’ll be another chance for us to improve the team. Maybe expectations should ramp up here. But for right now, I think this team is advancing. I’m happy with what I see so far.”

— On the team’s sights set on getting to a Super Bowl in the future: “I’m always going to want to go to the Super Bowl. Do I expect that? I want to be there. If you’re in this league and you’re not trying to get to the Super Bowl, and that isn’t your expectation from Day 1, then what the hell are you doing here? And that’s the mindset.”

— On 39-year-old backup quarterback Josh McCown, who is making $10 million this season but is the unquestioned leader in the locker room: “I think he’s money well spent.”

— On having no role in naming Darnold the starter and leaving it up to his coach and GM: “I’m not yet Jerry Jones.”

— On ticket sales with the Jets set to play their home opener Sunday against the Miami Dolphins: “They’re well ahead of where we were last year. I’m not going to go into details. This first game, we’re trending toward a sellout and I’m hoping we get there.”